data/problems/252.yml
---
:id: 252
:name: Convex Holes
:url: https://projecteuler.net/problem=252
:content: "Given a set of points on a plane, we define a convex hole to be a convex
polygon having as vertices any of the given points and not containing any of the
given points in its interior (in addition to the vertices, other given points may
lie on the perimeter of the polygon).\n\nAs an example, the image below shows a
set of twenty points and a few such convex holes. The convex hole shown as a red
heptagon has an area equal to 1049694.5 square units, which is the highest possible
area for a convex hole on the given set of points.\n\n ![]({{ images_dir }}/p252_convexhole.gif)\n\nFor
our example, we used the first 20 points (<var>T</var><sub>2<var>k</var>−1</sub>, <var>T</var><sub>2<var>k</var></sub>),
for <var>k</var> = 1,2,…,20, produced with the pseudo-random number generator:\n\n<center><table
class=\"p252\">\n<tr>\n<td style=\"text-align:right;\">\n<var>S</var><sub>0</sub>\n</td>\n
\ <td>=<sub> </sub>\n</td>\n <td>290797<sub> </sub>\n</td>\n </tr>\n<tr>\n<td>\n<var>S</var><sub><var>n</var>+1</sub>\n</td>\n
\ <td>=<sub> </sub>\n</td>\n <td>\n<var>S</var><sub><var>n</var></sub><sup>2</sup>
mod 50515093</td>\n </tr>\n<tr>\n<td style=\"text-align:right;\">\n<var>T</var><sub><var>n</var></sub>\n</td>\n
\ <td>=<sub> </sub>\n</td>\n <td>( <var>S</var><sub><var>n</var></sub> mod
2000 ) − 1000<sup> </sup>\n</td>\n </tr>\n</table></center>\n\n_i.e._ (527, 144),
(−488, 732), (−454, −947), …\n\nWhat is the maximum area for a convex hole on the
set containing the first 500 points in the pseudo-random sequence? \n Specify your
answer including one digit after the decimal point.\n\n"